The present invention relates to a cage rotor of an asynchronous machine with an axially laminated core having grooves running essentially axially, in which an electrical conductor is located which, with the electrical conductors in other grooves, embodies short circuit rings on the respective end face sides of the laminated core and thus forms a cage rotor.
In asynchronous motors with cage rotors, which are employed in the higher speed range, the short circuit ring in particular proves to be a weak point on the rotor. In such cases irregular expansions occur on the short circuit ring caused by centrifugal forces, which become noticeable as non-recoverable changes and to this extent as imbalance in the rotor. This occurs above all in short-circuit rings which use pure aluminum (AL99.5) as their electrically-conducting casting compound. In such cases, although the electrical conductivity value is comparatively high, this material is not suitable for high centrifugal stress.
It would therefore be desirable and advantageous to obviate prior art shortcomings and to provide an improved cage rotor of an asynchronous machine which both withstands the centrifugal stresses and also exhibits comparatively few losses.